Coating compositions find use in various industries including the coating and/or painting of motor vehicles. In these industries, and in the automotive industry in particular, considerable efforts have been expended to develop coating compositions with improved performance (both protective and aesthetic) properties. In the automotive industry, coatings have been applied to various component substrates for both protective and aesthetic purposes. Coatings are used to protect vehicle components against cosmetic damage (e. g., denting, scratching, discoloration, etc.) due to corrosion, abrasion, impacts, chemicals, ultraviolet light, and other environmental exposure. Additionally, color pigmented and high-gloss clear coatings typically further serve as decorative coatings when applied to vehicle body substrates. Multi-component composite coatings (for example, color-plus-clear composite coatings) have been used extensively to these ends. These multi-component coatings may include up to six or more individually applied coating layers over the substrate by one or more coating methods, including either electrophoretic or non-electrophoretic coating methods.
Polyurea elastomers have been among the coating compositions commercially applied to various substrates to provide protection to the substrates and to improve properties of the substrates. Polyurea compositions have been used as protective coatings in industrial applications for coating of process equipment to provide corrosion resistance or as caulks and sealants in a variety of aggressive environments. In addition, polyurethane elastomers have been used to line rail cars and truck beds. Such coatings for rail cars and trucks provide protection from cosmetic damage as well as protection from corrosion, abrasion, impact damage, chemicals, UV light and other environmental conditions.
However, certain prior art polyurea coating systems have been known to have deficiencies that inhibit their effectiveness in providing adequate protection to the substrate or to improve properties of the substrate. For example, known polyurea coating compositions may have relatively high viscosity that inhibits flow over the substrate or other underlying coating compositions. Also, certain polyurea coating compositions may have poor adhesion properties to a previously applied coating or to the substrate itself.
Accordingly, it is desirable to provide polyurea coating compositions that may enhance adhesion to previously applied coatings or to the substrate, and/or have a relatively lower viscosity that improves the flowable state of the coating composition for a longer period of time.